SR 520 pontoon repair costs announced

The Washington State Department of Transportation have announced the cost of repairing four pontoons from the first construction cycle and modifying another four from the second cycle for the new State Route 520 floating bridge.

The WSDOT acknowledged that it was a design error and not local workers that led to cracks in the first cycle of pontoons built in Aberdeen. At that time, WSDOT estimated repairs would cost tens of millions of dollars.

WSDOT will pay $48.8 million to complete the repairs on Cycle 1 pontoons. The addition of “transverse post-tensioning” to each of the 21 longitudinal pontoons constructed for the new floating bridge has been underway since June to help keep construction moving. In the first cycle, these pontoons were post-tensioned lengthwise only. For Cycles 2-6, each longitudinal pontoon will be post-tensioned fully within the Aberdeen casting basin.

WSDOT will also pay an additional $22.4 million for adding post-tensioning to four pontoons while they are in Aberdeen. The work was completed prior to float-out in April.

Both costs will be paid from the SR 520 risk reserve developed to address unforeseen project issues as part of the $2.7 billion program budget. With these charges paid, the current reserve is now $100 million.

Because of the delays, the new floating bridge is now estimated to open to traffic in late 2015 or early 2016.